Tuyere replacement apparatus



Aug. 5, 1969 DA|$HU KITAJIMA ET AL 3,458,918

TUYERE REPLACEMENT APPARATUS Filed Aug. 29, 1967 FIG.

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United States Patent ()fiice 3,458,913 Patented Aug. 5, 1969 11.5. Cl.29-239 7 Claims ABSTRACT OF THE DISCLOSURE This invention concerns atuyere replacement apparatus comprising a mandrel equipped with adrawing jig at one end and securely fixed to the rod of an opening andclosing cylinder of the other. Said mandrel is contained within a hollowdrawing rod which has a push-in fixture at one end. The inventionfurther comprises a reciprocating air hammer which is movably fitted tothe intermediate portion of said drawing rod, and two pull and pushcylinders which are disposed with said hammer interposed be tween them.The apparatus is constructed so as to effect the horizonal shifting ofsaid mandrel and drawing rod, and also, so that said air hammer willexert an impact on the drawing rod.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to an apparatus for inserting and withdrawing a tuyere from ablast furnace. More particularly the invention relates to a tuyerereplacement apparatus, so adapted as to apply an impact force to thetuyere, by means of an air hammer, when inserting or withdrawing thetuyere from the blast furnace.

Description of the prior art Previously, the replacement of a tuyere ofa blast fur nace for manufacturing iron has been a difiicult operation.It has required a great deal of force and a considerable amount of time.Said difliculty, has resulted from the narrow working space, the highambient temperature and the tuyere being heavy. The general methodpreviously used for replacing the tuyere is as follows.

A hook having a striker weighin approximately 150 kilograms connected toit is engaged with tuyere and drawn by approximately six to eightworkmen. During the drawing, impact it imparted to the tuyere bystriking it with the striker. Besides requiring a long period of time,this operation can be dangerous.

Attempts to mechanize the operation of replacing the tuyere apparatusinclude: a method of drawing the tuyere gradually be applying a steadyforce by means of an oil pressure cylinder or the like; a method ofdrawing the tuyere while imparting impact and oscillation; etc. Suchmethods have been tested, but have not yet been put to practical use.

The general method, set forth above, requires a long period of time toreplace the tuyere. Consequently, it is necessary that the hot blast ofthe furnace be suspended for a long period of time. To improve theoperating efficiency of the blast furnace, it is, necessary to carry outthe replacement of the tuyere in as short a period of time as possible.

Studies of said problem have led the present inventors to the discoverythat it requires a large force of approximately 20 to tons to withdrawthe tuyere quietly without exerting any impact in the tuyere replacementoperation. This finding is attributed to the fact that the majority oftroubles involving the tuyere have been caused by the melting lossthereof. In this case, slag, pig iron and the like are deposited on thetuyere and hence it requires a large force to separate them therefrom.

From the fact described above it is seen that it is not easy to withdrawthe tyuere without applying some impact because the apparatus requiredfor such withdrawing would be enormous. Accordingly, the simplest andmost advantageous way to withdraw the tuyere is to separate the tuyerefrom the metal Wall cooling fittings of the furnace wall by imparting animpact to the tuyere. The tuyere replacement apparatus, according to thepresent invention has been constructed with this in mind. The troublesassociated with the tuyere as described above usually occur only once ortwice in a month. However, to

obviate said troubles, it has been necessary to secure from seven toeight workmen to provide for an emergency. This necessity results in agreat loss in the working efficiency and creates a problem regarding theeffective use of personnel. On the other hand, the present inventionmakes it possible for as few as one or two workers to accomplish thetuyere replacement. Accordingly, the drawback described above is solved.

SUMMARY OF THE INVENTION It is an object of this invention to provide anapparatus, for replacing the tuyere in a blast furnace, which exertsimpact while applying a pushing or pulling force in the replacementoperation and which can be operated by as few as one or two workers.

It is a further object of this invention to provide a simple apparatuswhich can be used for withdrawing or attaching the tuyere to the blastfurnace in a safe and eflicient manner.

These objectives are accomplished by utilizing a tuyere replacementapparatus comprising a mandrel equipped with a drawing jig at one endand securely fixed to the rod of an opening and closing cylinder at theother. Said mandrel is contained within a hollow drawing rod which has apush-in fixture at one end. The invention further comprises areciprocating air hammer which is movably fitted to the intermediateportion of said drawing rod, and two pull and push cylinders which aredisposed with said hammer interposed between them. The apparatus isconstructed so as to effect the horizontal shifting of said mandrel anddrawing rod, and also, so that said air hammer will exert and impact onthe drawing rod.

BRIEF DESCRIPTION OF THE DRAWINGS The apparatus of the present inventionwill be more fully understood by referring to the following descriptiontaken in conjunction with the appended drawings, in which:

FIGURE 1 is a plan view, partly in section, of an apparatus embodyingthe present invention;

FIGURE 2 is a sectional view taken on line IIII of FIGURE 1; and

FIGURE 3 is a side elevation view, partly in section, showing theapparatus of the present invention mounted on a truck.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGURES 1, 2and 3, which show the apparatus of the present invention, the mainportion thereof comprises a cylindrical air hammer 1, a hollowcylindrical drawing rod 2 which extends through the bore of said airhammer, and is slidable therein an opening and closing piston cylindermeans 7 secured to one end of said drawing rod 2, and a mandrel 3 whichis directly connected to the rod (not shown) of said opening and closingpiston cylinder means 7 and which extends through the bore of saiddrawing rod 2 and,is slidable therein. A drawing jig 13 is mounted onone end of said mandrel 3 and a pull-out and push-in air cylinder 8 issecured to both sides of said air hammer 1. In the present apparatus,thus constructed, the mandrel 3 is moved horizontally by the operationof the opening and closing cylinder 7. The drawing jig 13 is connectedto the forward end of the mandrel 3, to open and close so as to engagewith or disengage from the tuyere 5. On the other hand, by the operationof the pull-out and push-in cylinders 8, the air hammer '1 is caused toslide horizontally to impart impact forces to the drawing rod 2 by wayof the impact receivers 17 mounted on rod 2.

Guide rollers 4 are mounted on plates 14 and guide the drawing rod 2,and a fixture 6 is in engagement with the tuyere 5. The fixture 6 can bea metal article, a link device or the like, and is positioned at theforward end of the drawing rod 2. Reference numeral 9 indicates the rodsconnected to the pistons (not shown) in air cylinders 8. Both ends ofeach rod 9 are secured to the supporting plate 14 by means of bolts. Thepull and push air cylinders 8 slide horizontally on said rods 9 by meansof the pistons in said cylinders 8. Reference numeral 10 indicates guiderods extending between plates 14 and on which the air hammer 1 isslidable. Guide rods 10 extend past one plate 14 toward the fixture 6and have one set of guide rollers 4 mounted thereon. The pull and pushcylinders 8 are bolted to the air hammer 1 and slide horizontally alongthe drawing rod 2 together with the hammer which, in turn, strikes theleft or right impact receiver 17. Reference numeral 15 indicates aflange mounted on the drawing rod 2 and coupled to the fixture 6 by acompression spring 16. The present apparatus is mounted on a truck 12having a handle 18 for adjusting the height through a conventionaldouble screw crossed lever lifting device and wheels 19 on which theapparatus rolls as shown in FIGURE 3. 'In order to provide for areaction force at the time of inserting or withdrawing the tuyere thetruck 12 is connected to the furnace body by means of the fasteners '11on said truck 12. However, the present apparatus may be, provided on anysuitable transportation means other than the truck 12.

The action of said apparatus, constructed as mentioned above, is asfollows. Considering first, the operation of withdrawing the tuyere 5,after said apparatus is adjusted for the proper horizontal position andheight, the drawing jig 13 is inserted through the tuyere 5 and fixture6 is engaged with the outside end of the tuyere 5, as shown in FIGURE 3.Compressed air is then supplied to the air cylinder 7 to move the pistonof cylinder 7 toward the left. Then the mandrel 3, directly connected tothe rod (now shown in the drawing) of said cylinder 7, is shifted to theleft, causing the drawing jig 13, which is mounted 4 on the forward endof said mandrel 3 to open, as shown in FIGURE 1, so that the hookportions on the end are engaged with the forward end of the tuyere 5.

Compressed air is supplied to the pull and push air cylinders 8 to causesaid cylinders 8 to move to the left along the rods 9. Said workingforce is transmitted to the shuttling air hammer 1 which is securelyfastened to the pull and push cylinders 8 causing said hammer 1 to exerta steady force on the left impact receiver 17 while beating it. By saidheating a working force plus an impact force is imparted to the drawingrod 2 which is securely connected to said impact receiver '17. Saidmotion draws the tuyere 5, engaged by the forward end of the drawing jig13, strongly to the left. It is, of course, possible to impart thesteady force to the tuyere without the impact force by simply notoperating the hammer.

The operation of inserting the tuyere 5 into the blast furnace will beconsidered next. Said operation is performed by steps in the operationof withdrawing the tuyere. As shown in FIGURE 1, the tuyere 5 is heldbetween the push-in fixture 6 and the drawing jig 13 and positioned inthe proper position for being inserted in the blast furnace. The pulland push cylinders 8 are operated to move to the right causing thedrawing rod 2 to push the flange 15 to the right. This motion compressesthe spring 16 and brings the flange into direct contact with the pushinfixture 6. The pushing force of the pull and push cylinders 8 is thustransmitted to the tuyere 5. In this case, impact can be applied by theair hammer 1 while the pushing force is applied to the tuyere 5.

As described above, the operation of the present apparatus is simplethus making it possible for as few as one or two workmen to withdraw orinsert the tuyere in a short period of time. Since it is possible toimpart a pulling or pushing force as well as an impact by the use ofcompressed air, it is possible to construct the present apparatus sothat it is small in size and so that it can perform the replacement ofthe tuyere in an extremely efiicient manner.

What is claimed is:

1. An apparatus for inserting and removing a tuyere from a blastfurnace, comprising a tuyere holding means having relatively movableportions to engage the opposite ends of the tuyere therebetween to holdthe tuyere, means coupled to one of said portions for moving it relativeto the other portion, an inserting and withdrawing rod on which saidtuyere holding means is mounted, impact producing means slidably mountedon said rod, force receiving means on said rod against which said impactmeans is abuttable, force exerting means connected to said impactproducing means for exerting a force on said impact producing meanswhich is transmitted through the impact producing means to said rod, andframe means on which said force exerting means is mounted and adapted tobe secured to produce a reaction force to the force of said forceexerting means.

2. An apparatus as claimed in claim 1 in which said impact producingmeans comprises an impact hammer, and said force receiving meanscomprises two spaced impact receivers on said rod, said impact hammerbeing slidable along said rod between said impact receivers.

3. An apparatus as claimed in claim 2 in which said force exerting meanscomprise a pair of fluid pressure piston cylinder members which canexert a force in either direction and which have a single rod extendingtherethrough and which are mounted on said frame means, the cylinders ofsaid members being connected to said air hammer and being movable alongthe rods.

4. An apparatus as claimed in claim 1 in which said one portion of saidtuyere holding means comprises hook means for engaging the inner end ofthe tuyere and which extends through the tuyere, and said means formoving said one portion relative to the other portion comprise a rodcoupled to said hook means, and a fluid pressure piston on said rod anda fluid pressure cylinder around said piston, said fluid pressurecylinder being mounted on References Cited said frame means.

5. An apparatus as claimed in claim 1 in which said UNITED STATESPATENTS other portion of said tuyere engaging means comprises 2,561,5777/1951 Knudsen 29-254 X a tuyere engaging fixture, a spring engagingsaid fixture, 5 3,067,502 12/1962 Whemkw 29255 and a flange on said rodengaging said spring. 3,156,038 11/1964 fl i 29-234 6. An apparatus asclaimed in claim 1 in which said 3157O70 11/1964 Heldnch 173*112 framemeans includes means for connecting said frame means to a blast furnaceto hold the frame means While ROBERT RIORDON Primary Examiner said forceexerting means is operating. 10 J. C. PETERS, Assistant Examiner 7. Anapparatus as claimed in claim 1 in which said frame means includes aplatform and means to raise and U.S. Cl. X.R.

lower the platform. 29252, 255

